I first heard about Mandelbrot as an undergrad in the early 80's as fractals became the mathematical curiosity du jour. One of the popular screen savers on the Sun computers in the late 80's was either zooming in on the Mandelbrot set to reveal the same set inside. One could spend hours watching--this and Tetris wasted many grad student hours in those years before Facebook and Twitter.

I saw Mandelbrot speak just once in 1996 at a 50th Anniversary of CWI celebration, also the only time I've seen Knuth give a talk. All I remember from the talk were pretty pictures of imaginary fractal mountains on other planets generated by Mandelbrot for some movie--shades of Avatar.

I always thought of fractals as mostly descriptive--yes, fractals appear almost everywhere, but so what? Nevertheless here's to a very uncommon mathematician who literally showed us the beauty of mathematics.